Efficiency

Using the efficiency results from the previous page, we plotted a chart that shows the HCP-850's efficiency at low loads and loads equal to 20%-100% of the PSU's maximum-rated load.



The HCP-850 can easily compete with the Platinum competition at both low- and normal loads.

Efficiency at Low Loads

In the next tests, we measured the HCP-850's efficiency at loads much lower than 20% of its maximum-rated load (the lowest load the 80 Plus Standard measures). The loads we dialed were 40 W, 60 W, 80 W, and 100 W (for PSUs with a capacity higher than 500 W). This is important for settings where the PC sits in Idle with Power Saving turned on.

Output noise was kept low at low loads despite the high ambient at which we conduct the above tests. Efficiency was also at very good levels. We measured efficiency well above the 80% mark in three out of the four tests, which is noteworthy for even a Platinum unit.

5VSB Efficiency

The ATX specification states that 5VSB efficiency should be as high as possible and recommends 50% or higher efficiency with 100 mA of load, 60% or higher with 250 mA of load, and 70% or higher with 1 A or more of load.

We will take four measurements: one at 100, 250, and 1000 mA, each, and one with the full load the 5VSB rail can handle.

The 5VSB rail was very efficient and even managed to crack the 80% mark in the last two tests.

Power Consumption in Idle & Standby

In the table below, you will find the power consumption and the voltage values of all rails (except -12V) when the PSU is in idle mode (powered on but without any load on its rails) and the power consumption when the PSU is in standby mode (without any load on 5VSB).

Vampire power was low.

Fan RPM, Delta Temperature & Output Noise

The cooling fan's speed (RPMs) and the delta difference between input and output temperature are illustrated in the following chart. The following results were obtained at 38°C-45°C ambient.



A chart that shows the cooling fan's speed (RPMs) and the output noise follows. We measured the fan's noise at a distance of 1 meter, inside a small custom-made anechoic chamber whose internals are completely covered in specialized soundproofing material (Be Quiet! Noise Absorber Kit). Background noise inside the anechoic chamber was below 20 dBA during testing, and the results were obtained with the PSU operating at 38°C-45°C ambient.



The following graph illustrates the fan's output noise throughout the PSU's entire operating range. The same conditions as in the above graph apply to our measurements, but the ambient temperature was in-between 28°C and 30°C.



As you can see in the above graph, the PSU is near-silent under normal conditions. Delta's fan only makes its presence known at higher loads and is silent enough at light and mid-high loads.